Below are charts showing patients notified to NSW Health with a particular communicable disease. The infectious disease is only notified by laboratories when they find that a person tests positive to this condition. The first graph shows the number of notifications by month from January 2011 to May 2015. The two most common strains of the causal agent are shown separately on the graph. The second graph shows the age and gender of patients notified in the last year.
What is the disease …
Answer
The graphs show consistent annual peaks in case notifications in the middle of each year, but few notifications at other times. The number of cases reported in each peak varies considerably, particularly for cases caused by the blue strain. Cases are notified across all age groups, and are evenly distributed by gender, although there are about twice as many cases notified in the under 5 year age group compared to other 5 year age groups, and slightly more elderly women are notified with the disease than men.
The disease is influenza, in NSW caused mainly by influenza A (in blue) and less commonly influenza B (in red). Influenza outbreaks typically peak in winter, although can begin in late autumn or extend into spring. While very young children do have higher rates than other age groups, they are probably more likely than other age groups to present to hospital and be tested for respiratory viruses including influenza.
See more information on influenza surveillance and prevention.
